For Paul Boken, Samsung's announcement Friday that some models of its flagship smartphone will include a built-in feature to remotely disable the device if it's stolen was evidence of a painful tide turning.

"It's a sign there is momentum building to make sure the problem is addressed," Boken said. His 23-year-old daughter, Megan, was shot and killed for her smartphone on Aug. 18, 2012, as she sat in her car near a friend's house in St. Louis, where she attended college and was a star volleyball player. She was talking to her mother at the time.

"I will never forget that day," Boken said by phone Friday from the Chicago law firm where he works. "So many people view (smartphone theft) as an intellectual issue. No. It's real life."

Megan Boken's phone was one of about 1.6 million mobile devices stolen in the United States in 2012, according to figures from Consumer Reports.

San Francisco District Attorney George Gascón, who since 2012 has been pushing the wireless device industry to incorporate a "kill switch" to render the devices useless after they're stolen, has described the thefts as "a national epidemic."

Because of their high resale value on secondary markets, mobile devices, including tablets, account for about 60 percent of all robberies in San Francisco, and up to 75 percent in Oakland, law enforcement officials say.

"If there were no cell phone robberies, violent crime would be down by double figures," San Francisco Police Chief Greg Suhr said in January.

Gascón has joined with New York Attorney General Eric Schneiderman in trying to get wireless carriers and manufacturers to agree to antitheft measures.

That's a step U.S. carriers had resisted until Friday, when two of them, Verizon Wireless and U.S. Cellular, joined Samsung in supporting the new antitheft features for the Galaxy S5 smartphone, which was available for pre-orders online Friday and will be released April 11.

Preloaded features

The new phones for those two carriers will be preloaded with the Find My Mobile and Reactivation Lock features, which users can activate for free and lock the phone if there is an unauthorized attempt to reset it.

"Samsung takes the issue of smartphone theft very seriously, and we are continuing to enhance our security and anti-theft solutions," the company said in a statement.

Last June, Apple became the first manufacturer to heed the chorus of law enforcement officials calling for a kill switch, or activation lock, as Apple calls it, on its mobile devices.

Samsung's step, while welcomed by Boken, Gascón and others, was also described as only a partial advancement - in part because, like Apple's approach, it requires the customer to engage the feature, rather than having it be a default, or opt-out, service.

Restrained praise

"More work needs to be done to ensure these solutions come standard on every device, but these companies have done the right thing by responding to our call for action," Gascón and Schneiderman said in a joint statement. "No family should lose a mother, a father, a son or a daughter for their phone."

A bill that state Sen. Mark Leno, D-San Francisco, introduced in February would require any smartphone or tablet sold in California to have a kill switch and that the system be opt-out, meaning customers would have to take steps to disengage it.

That's key, according to Gascón and others, in making the devices widely unusable if stolen, thereby removing the incentive to take them.

"This is a crime of convenience. If we end the convenience, we end the crime," Leno said in a recent interview. It has become his mantra for the bill, SB962, which was approved by the Senate's Energy, Utilities and Communications Committee on Tuesday on a 6-2 vote.

CTIA-the Wireless Association, a trade group for wireless providers, says kill switches leave devices open to hacking and raise privacy concerns. Representatives for the association or other wireless carriers could not be reached for comment Friday, but they have called for national stolen-device databases as part of the solution.

Sprint spokeswoman Crystal Davis said earlier in an e-mail that "while open to a kill switch option, Sprint remains concerned that 'permanent' kill switches could lead to unintended consequences for customers, reputable recycling programs and legitimate used or trade-in devices, given that many devices reported lost or stolen are subsequently found by their owners."

Gascón criticized such arguments as "disingenuous." He praised device manufacturers such as Samsung for being willing to tackle the problem but said wireless carriers appeared to be more concerned with their bottom line than the safety of their customers.

Profit generator

Lost or stolen phones are big business, officials say.

The top four U.S. wireless carriers have about $7.8 billion in annual revenue from insurance protection plans, and a kill switch would cost the industry an estimated $2.5 billion on insurance products alone, Gascón said.

The U.S. smartphone industry as a whole is worth $60 billion a year, and an estimated $30 billion of that is due to lost or stolen devices, Gascon said.

"There's a lot of money involved here," Gascón said. "About half of their industry is based on a business model that involves the consumer being hurt or victimized."